In recent years, as advances in semiconductor miniaturization and acceleration are made, there is a growing tendency for ever-greater amounts of data to be communicated between devices, or between LSI circuits equipped on a device. However, the influence of packaging overhead imposes a strict limit on the number of LSI terminals (pads). As such, in order to realize greater data transfer speeds with a reduced number of LSI terminals, interface standards making use of serial transfer have become widespread.
Generally, bus connections are difficult to achieve for serial transfers. One possible solution is using ring topology in order to connect a plurality of node devices. In ring topology, any node device (i.e., repeater) connected between the node device serving as the data transmission source and the destination node device must remain active in order to perform data relay processing. Thus, conventional technology for reducing the electric power consumption of node devices serving as repeaters has the logical layer (link controller), being unnecessary for relay processing, maintain a reset state, while the physical layer (PHY) performs the relay processing. Patent Literature 1 discloses an example of such technology.